Wireless communication system for air distribution system

ABSTRACT

A hierarchical control system including a central receiver; a first communications medium operably connecting the central receiver to at least one controller; and a controller operably connected to the central receiver by the first communications medium. The system also includes a sensor for sensing conditions; a second communication medium; and a transmitter for transmitting the sensed conditions from the sensor to the central receiver via the second communications medium. The central receiver also includes receiver for receiving transmissions on the second communications medium and a transmitter for retransmitting the transmissions on the first communications medium.

BACKGROUND OF THE INVENTION

The present invention is directed to an air distribution system for anair conditioning system, and more particularly, to a wirelesscommunication system between the air distribution controllers and thezone temperature sensors in the zone to be controlled.

Typical air handling systems rely on a physical connection between eachzone sensor and each air handling unit controller. This physicalconnection is difficult, time consuming, and expensive to installbecause it is generally located within the support walls and ceiling ofthe structure whose air is to be conditioned. Its location within thestructure makes the physical connection difficult to maintain, difficultto upgrade, and difficult to retrofit to an existing installation. Infact, the installation costs for installing the physical connection andthe zone sensor is typically triple or quadruple the cost of the zonesensor and the physical connection.

Additionally, the location of the physical connection within a wallmakes it extremely difficult to change the physical connection inresponse to an advance in technology. Furthermore, the controller forthe air handling unit of the air distribution system is thereafterdependent on and limited to the type of physical connection, as well asto the particular zone sensor the controller is connected to and theparticular location of the zone sensor.

SUMMARY OF THE INVENTION

It is an object, feature and advantage of the present invention to solvethe problems of prior art communication schemes for air distributionsystems.

It is an object, feature and advantage of the present invention toeliminate the physical connection between the zone sensors and thecontroller of the air handler or air handling terminal unit of an airdistribution system.

It is an object, feature and advantage of the present invention toprovide a zone sensor with reduced installation costs.

It is an object, feature and advantage of the present invention toprovide a zone sensor which can be easily relocated in response tochanges in the air distribution system.

It is an object, feature and advantage of the present invention toprovide a zone sensor which can be easily relocated in response to theenvironment being conditioned.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich can be easily retrofit to existing installations.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich can be easily upgraded in response to changing technology.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich allows a controller for an air distribution system to operateindependently of a particular zone sensor.

It is an object, feature and advantage of the present invention tooperate an air distribution system using a designated master setpointresponsive to a plurality of zone sensors.

It is an object, feature and advantage of the present invention toprovide an air distribution system including a master setpointrepresentative of a plurality of zone sensor setpoints.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich allows a controller of the air distribution system to operateindependently of the location of a particular zone sensor.

It is an object, feature and advantage of the present invention toprovide the controller of an air handling unit with alternate zonesensors for use when the primary zone sensor fails in any way.

It is an object, feature and advantage of the present invention toprovide a wireless communication system which allows the controller ofan air handling unit to operate using the inputs from a plurality ofzone sensors.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich allows a controller of the air distribution system to operate byaveraging the input of a plurality of zone sensors.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwhich allows the controller of an air distribution system to operate inconformity with the data from a majority of several predetermined zonesensors.

It is an object, feature and advantage of the present invention toprovide a hierarchical wireless communication scheme for an airdistribution system.

It is an object, feature and advantage of the present invention toprovide a wireless communication system which will operate with existingair distribution controller communication networks.

It is an object, feature and advantage of the present invention toprovide a hierarchical variable air volume communication system.

It is an object, feature and advantage of the present invention toprovide a default sensor arrangement for the controller of an airdistribution system.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemhaving at least two different communications medium.

It is an object, feature and advantage of the present invention toprovide a communication system for an air distribution having at leastthree different communications media.

It is an object, feature and advantage of the present invention to allowthe user of an air distribution system to inform the air distributionsystem of the user's personal comfort.

It is an object, feature and advantage of the present invention to allowthe controller of an air distribution system to respond to a user'spersonal comfort requirements.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemwith great range.

It is an object, feature and advantage of the present invention toprovide a one-way wireless communication system for an air distributionsystem.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemusing radio frequency as a communications medium.

It is an object, feature and advantage of the present invention toprovide a wireless communication system for an air distribution systemusing spread spectrum radio frequency transmissions as a communicationsmedium.

It is an object, feature and advantage of the present invention toprovide a two tier wireless communication system for an air distributionsystem using a hard wired communications bus as the first tier, and awireless communication scheme as the second tier.

It is an object, feature and advantage of the present invention toprovide a three tier communications system for an air distributionsystem using a hard wired bus as the first tier, a wirelesscommunication system as the second tier, and an infrared communicationsystem as a third tier.

It is an object, feature and advantage of the present invention toprovide a central receiver on a hard wired communications bus whichreceives wireless transmissions from the zone sensors.

It is an object, feature and advantage of the present invention toprovide a wireless communication system including redundant receivers.

It is an object, feature and advantage of the present invention toprovide a generic sensor input.

It is an object, feature and advantage of the present invention toprovide a wireless communications system for an air distribution systemwhich facilitates air balancing.

It is a further object, feature and advantage of the present inventionto provide a wireless communication system including redundant receiversconnected by a hard wired communications bus.

It is an object, feature and advantage of the present invention toprovide a wireless communication system including a backup receiver toensure the receipt of wireless transmissions from zone sensors and thelike.

It is an object, feature and advantage of the present invention toprovide a setup tool for programming components of a wirelesscommunications system.

It is an object, feature and advantage of the present invention toprovide a setup tool which programs a wireless communications systemsusing wireless communications.

It is an object, feature and advantage of the present invention toprovide a setup tool which programs a wireless communication system bymeans of a physical connection to any one of a plurality of thecomponents of the wireless communications system.

It is an object, feature and advantage of the present invention toprovide a setup tool in a one-way wireless communications systems whichuses an audible signal or signals as a form of acknowledgement to theuser of the setup tool.

It is an object, feature and advantage of the present invention toprovide a wireless communication system whose receivers and transmittersare substantially independent of location.

It is an object, feature and advantage of the present invention tominimize the number of receivers required by a wireless communicationsystem.

It is an object, feature and advantage of the present invention toreduce the component costs of a wireless communication system byreducing the number of receivers needed by the wireless communicationsystem.

It is an object, feature and advantage of the present invention to allowan individual to indicate lighting level comfort.

It is an object, feature and advantage of the present invention toprovide a building automation and control system which is responsive tothe comfort needs of an occupant on an individual basis.

The present invention provides a hierarchical control system including afirst central receiver, a first communications medium operablyconnecting the first central receiver to at least one controller and acontroller operably connected to the first central receiver by the firstcommunications medium. The system also includes a first sensor forsensing conditions, a second communication medium, and a transmitter fortransmitting the sensed conditions from the first sensing means to thefirst central receiver via the second communications medium. The firstcentral receiver includes a receiver for receiving transmissions on thesecond communications medium and a transmitter for retransmitting thetransmissions on the first communications medium.

The present invention also provides a system for transferringinformation from a sensor to a controller. The system includes a firstcommunications medium, a second wireless communications medium, acontroller operably connected to the first communications medium and areceiver operably connected to the first communications medium. Thereceiver includes a receiver for receiving communications on the secondcommunications medium and a transmitter for retransmittingcommunications from the second communications medium on the firstcommunications medium. The system includes a first sensor for sensingconditions, wherein the first sensor includes a transmitter fortransmitting the sensed conditions on the second communications medium.The controller is responsive to the first sensor by means of the firstand second communications medium.

The present invention additionally provides a building automation systemcomprising: means for conditioning air; and means for distributingconditioned air from said air conditioning means. The distributing meansincludes a first communications medium, and a plurality of controllersoperably connected to the first communications medium. At least some ofthe plurality of controllers each includes means for controlling the airdistribution. The building automation system also includes a secondwireless communications medium; at least one central receiver operablyconnected to the first communications medium. The central receiverincludes a receiver for receiving transmissions on the secondcommunications medium and a transmitter for retransmitting thecommunications from the second communications medium onto the firstcommunications medium. The building automation system also includes aplurality of sensors, each of which includes a sensor for sensingenvironmental conditions and a transmitter for transmitting dataindicative of the sensed conditions on the second communications medium.At least some of the plurality of controllers then controls thedistribution of air in accordance with the transmitted data.

The present invention further provides a method of controlling anenvironment. The method comprises the steps of: determining, with atleast a first sensor, the environmental conditions in each of aplurality of zones; transmitting signals indicative of the environmentalconditions from each of said plurality of zones to a central receiver bymeans of a second communications medium; receiving the environmentalconditions at the central receiver from the second communicationsmedium; retransmitting the environmental conditions from the centralreceiver onto a first communications medium; receiving in each of aplurality of controllers the retransmitted environmental conditions onthe first communications medium; and controlling the environment of aparticular zone in accordance with a predetermined portion of theenvironmental conditions.

The present invention also provides a setup tool for programming abuilding automation system having a central receiver operably connectedto a plurality of controllers by a first communications medium. Thecentral receiver is operable to receive transmissions on a secondcommunications medium. The setup tool comprises: means for constructingprogram instructions for one of the plurality of controllers; and atransmitter, operably connected to the construction means, fortransmitting the programmed instructions to the central receiver bymeans of second communications medium.

The present invention also provides a zone sensor for providinginformation regarding an environment to be conditioned to a controller.The zone sensor comprises: a housing; a transmitter associated with thehousing, for transmitting wireless communications on a secondcommunications medium; a sensor, associated with the housing, formonitoring environmental conditions such as temperature; and means,associated with the housing and operably connected with the transmittingmeans and the monitoring means, for initiating wireless transmissions ofenvironmental conditions and instructions upon a timed or change ofstate basis.

The present invention additionally provides a controller which isoperable independent of a particular zone sensor. The controllercomprises: a housing; means, associated with the housing, for actuatinga device to be controlled; means, associated with the housing, forprogramming the controller with an indication of a plurality ofavailable zone sensors; means, associated with the housing, forselecting a control algorithm from a plurality of control algorithms;and means, associated with the housing, for operating the controller inaccordance with the selected control algorithm and the indicated zonesensors.

The present invention further provides a sensor including: a housing; acontroller associated with the housing; and a temperature sensorassociated with the housing and operatively connected to the controller.The sensor also includes a power supply operatively connected with thecontroller and associated with the housing; and a wireless transmitterassociated with the housing and operatively connected with thecontroller. The sensor also includes means, associated with thecontroller and the power supply, for entering a dormant state of lowpower consumption, and means, associated with the controller and powersupply, for automatically awakening from the dormant state.

The present invention further provides a method of balancing an airdistribution system. The method comprises the steps of: (A) providing aplurality of devices, each capable of controlling the airflow throughducts; (B) determining an optimum or balanced airflow setpoint for eachof the ducts; (C) identifying the optimum or balanced airflow setpointfor each of the ducts to the respective controlling device; (D)distributing air through the air distribution system; (E) measuringairflow in the ducts; (F) reporting measured airflow to a respectivecontrolling device; (G) initiating, at substantially the same time, acomparison by each of the controlling devices of measured airflow andoptimum or balanced airflow; (H) controlling the airflow in the variousducts to minimize the difference between measured airflow and optimum orbalanced airflow setpoint; (I) repeating steps e, f, g and h until theair distribution system is balanced; and (J) customizing the airbalancing system in response to indications of personal discomfort orenvironment changing conditions.

The present invention also provides a method of controlling an HVACsystem. The method comprises the steps of: distributing conditioned airto a plurality of zones; controlling the flow of conditioned air to eachof the plurality of zones with a plurality of controllers; operablylinking the controllers with a first communications medium; monitoringthe effect of the conditioned air in each of the plurality of zones withat least one sensor; transmitting the monitored effects on a secondwireless communications medium; receiving the transmissions on thesecond communications medium in a central receiver; retransmitting themonitored effects from the central receiver on the first communicationsmedium; and receiving the monitored effects from the firstcommunications medium in the plurality of controllers.

The present invention additionally provides a hierarchical controlsystem including a central receiver; a first communications mediumoperably connecting the central receiver to at least one controller; anda controller operably connected to the central receiver by the firstcommunications medium. The system includes a first sensor for sensingconditions; a second communication medium and a transmitter fortransmitting the sensed conditions from the first sensor to the centralreceiver via the second communications medium. The central receiverincludes a receiver for receiving transmissions on the secondcommunications medium and a transmitter for retransmitting thetransmissions on the first communications medium. The system alsoincludes a third communications medium; a second sensor for sensingconditions. The second sensor includes a transmitter for transmittingthe sensed conditions on the third communications medium. The firstsensor includes a receiver for receiving sensed conditions transmittedon the third communications medium and means for retransmittingtransmissions from the third communications medium on the secondtransmissions medium. The system also includes a generic sensor inputand means for identifying and processing generic sensor data.Additionally, the system includes a setup tool for providing programminginstructions for the controller, and a transmitter for transmitting theprogramming instructions on the second or third communications medium.

The present invention also provides a method of providing personalcomfort control in an air conditioning system having a plurality ofzones where each zone has at least one controller controlling theenvironment of the zone, the method comprises the steps of: sensing atleast one environmental condition in the zone; transmitting the sensedcondition to the controller by wireless transmission; and controllingthe environment of the zone in response to the sensed condition.

The present invention additionally provides a method of controlling theenvironment of a plurality of zones while responding to individualpersonal comfort requirements within each zone. The method comprises thesteps of: repeatedly providing a zone controller with zone data and usercomfort data by wireless transmission; controlling the environment ofeach zone in accordance with the zone data; and subsequently modifyingat least a portion of the environment of a particular zone in accordancewith user comfort information.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram of a typical air conditioning and distributionsystem.

FIG. 2 shows a single zone of an air handling system incorporating thepresent invention.

FIG. 3 shows a block diagram of the preferred embodiment of the presentinvention.

FIG. 4 shows a block diagram of the hierarchical communication system ofthe present invention.

FIG. 5 shows an example of the invention as described in FIGS. 2 through4.

FIG. 6 is a table showing the data packet transmitted by a zone sensor.

FIG. 7 shows the hierarchical structure of FIG. 4 further including acoordinating controller.

FIG. 8 shows the hierarchical structure of a second preferred embodimentof the present invention including first, second, and thirdcommunication media.

FIG. 9 is a table showing the data packet transmitted by a personalcomfort sensor.

FIG. 10 shows an example of the second preferred embodiment of thepresent invention.

FIG. 11 shows the hierarchical structure of a third embodiment of thepresent invention.

FIG. 12 shows an example of the third embodiment of the presentinvention.

FIG. 13 shows a zone data packet for one zone sensor and two personalcomfort sensors.

FIG. 14 shows the operation of a controller being provided with datafrom a multiplicity of sensors.

FIG. 15 shows a hierarchical structure for the first embodiment of thepresent invention where several sensors provide a single controller withdata.

FIG. 16 shows the operation of the central receiver.

FIG. 17 shows the operation of a typical zone or personal comfortsensor.

FIG. 18 shows a command data packet such as might be transmitted by abuilding automation system or by a setup tool.

FIG. 19 shows a setup tool for programming controllers in accordancewith the present invention.

FIG. 20 is a block diagram of the setup tool of FIG. 19.

FIG. 21 is a block diagram of the zone sensor of the present invention.

FIG. 22 is a block diagram of the personal comfort sensor of the presentinvention.

FIG. 23 is a block diagram of the central receiver of the presentinvention.

FIG. 24 is a block diagram of the controller of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a typical building 30 having an air distribution system 32.In this building 30 heat flows to and from the building interior througha series of heat transfer operations.

During normal cooling operation, heat enters each zone 34 from internalsources such as people 36, lights 38 and equipment 40, and from externalsources such as infiltration through walls 42, conduction through walls42, and radiation through windows 44. Warm air is removed from each zone34 by the return air stream 46 and is replaced by cool supply air from aterminal unit 48. At an air handler 50, warm return air rejects heat tocool water flowing within the heat exchange coil 52. The warm waterexiting from the coil 52 rejects its heat to refrigerant within a waterchiller 54 located elsewhere. The refrigerant in turn rejects heat to acondenser 56.

During normal heating operation, heat leaves each zone 34 and isreplaced by warm supply air from the terminal unit 48. A heating elementin the terminal unit 48 can supply the heat, or heat can be extracted atthe air handler 50 from water flowing within the heat exchange coil 52.

The basic control objective in the zone 34 controlled by an airdistribution system 32 is to add or subtract heat by means of theconditioned air supply so that the net amount of heat gained, lost, andstored within the zone 34 is balanced at a comfortable temperature.Conventional variations in this arrangement are contemplated such as,for example, (1) the elimination of the water chiller loop so that thereturn air itself is in heat exchange relationship with the refrigerant,or (2) the use of a cooling tower instead of the condenser 56.

First Embodiment

FIG. 2 shows, from a user's perspective, a single zone 34 incorporatingthe present invention. The single zone 34 includes a zone sensor 58having a microprocessor 61 and user selectable inputs for setpoint 60and mode of operation 62 (i.e. heating or cooling) as well as atemperature sensor 64 which monitors air temperature. The zone sensor 58is also shown in FIG. 21. The zone sensor 58 is usually located in afixed position which is both easily accessible to the user, andrepresentative of the temperature in the zone 34. As will subsequentlybe discussed, the zone sensor 58 may also include a generic sensor input49.

It should be recognized that the zone sensor 58 is preferably powered bya power source 59 such as a battery, and therefore the zone sensor 58either can be detachable from the representative location, or can bealways portable and have no fixed position. The power source 59 can alsobe a wired connection to an AC power supply or can be a connection toother power sources such as pneumatic or solar. If a battery powersource 59 is used, a battery level monitor 63 is also preferablyincluded. Additionally, if a non-renewable power source such as abattery 59 is used, a hardware timer interrupt is also preferablyincluded in the microprocessor of the zone sensor 58. The zone sensor 58is then able to enter a dormant state, akin to sleep, where minimalpower is used. Periodically (preferably on the order of a two secondinterval), the hardware timer interrupt activates the zone sensor 58,and the zone sensor 58 samples its environment by means of the availableinputs 60, 62, 64, 49. If the elapsed time since the last transmissionof data is less than 30 seconds, the zone sensor 58 then returns to itsdormant state. If the elapsed time since the last transmission of datais greater than five minutes, a mandatory transmission of data to acentral receiver 66 is made. If the elapsed time is greater than thirtyseconds but less than five minutes, a transmission is made if any of thefollowing criteria is met: (1) if the absolute value of the differencebetween the latest temperature and the temperature at the lasttransmission is greater than twice the temperature range resolution; (2)if the setpoint has changed 1° F. since the last transmission; or if asetup command from a setup tool 320 or a message from a personal comfortsensor 110 has been received. Other criteria are also contemplated.After sampling and after transmitting, the zone sensor 58 returns to thedormant state.

The zone sensor 58 has an objective to responsively communicateinformation and react to changes in zone conditions. To facilitate this,the zone sensor 58 includes a wireless transmitter 65. This wirelesstransmitter 65 is preferably a spread spectrum radio frequencytransmitter 65A, but may also be an infrared transmitter 65B, narrowband radio frequency transmitter 65C, or an ultrasonic transmitter. Atregular intervals or after a change of state or when required by a userto respond to a command, the zone sensor 58 uses the wirelesstransmitter 65 to transmit a wireless signal to a receiver portion 67 ofa central receiver 66. The central receiver 66 preferably includes aconventional microprocessor data controller 362 and associated RAM andROM memory 364.

The central receiver 66 receives the wireless signals from each of aplurality of zone sensors 58 in its receiver portion 67, reformats thosesignals in a translator portion 69 of the central receiver 66, andretransmits those signals on a first communications medium TX1, forexample, a hard wired communications bus 72 connecting the units of theair distribution system 32. The central receiver 66 is shown in FIG. 23as including a receiver portion 67 and a translator portion 69. Thereceiver portion 67 includes a TX2 receiver 360 which receivestransmissions on a second communications medium TX2; a data controller362 such as a TMS 320C14 microcontroller to control the acquisition oftransmission on the second communication medium TX2; and a power supply366. The translator portion 69 includes a data buffer and formatter 368such as a Mitsubishi M50747 microprocessor which receives data packetsfrom the data controller 362 and reformats them, if necessary, in theformat of the first communication medium TX1. A memory device 364 isprovided to store such information as valid transactions and lists ofvalid message transmitters, while an audible tone annunciator 365 isincluded to provide audible acknowledgements of commands received on thesecond communications medium TX2. The reformatted messages aredispatched by a TX1 transceiver 370 connected to the firstcommunications medium TX1. The transceiver 370 allows two waycommunication between the central receiver 66 and any device connectedto the first communications medium TX1. This allows a buildingautomation system 76 or the coordinating controller 102 of FIG. 7 toprogram or command the central receiver 66. Alternatively, the setuptool 320 of FIG. 19 can transmit program instructions or commands to thecentral receiver 66 over the second communications medium TX2.

FIG. 6 shows a data packet 86 included in the zone sensor's wirelesstransmission. This data packet 86 is preferably prefixed by a messagetype 86T and includes an indication of the zone sensor's identity 86A,the zone sensor's setpoint 86C, 86D, the zone sensor's mode of operation86E, and the current zone temperature 86B. The zone sensor 58 can alsotransmit information from the battery level monitor 63 indicating thepower level 86F of a battery 59 in the zone sensor 58, and an indicationof whether a user has initiated timed override 86G.

During unoccupied zone periods such as late at night, timed override 86Gallows a user, by touching a switch 70, to indicate to a controller 68of the zone air handling system that the zone 34 should temporarily betreated as occupied rather than unoccupied. After the expiration of apredetermined time-out period, the controller 68 automatically returnsthe zone 34 to the unoccupied status. A more sophisticated version oftimed override provides a multifunction way of allowing a user to drivethe system and to enter information to the system. In this version theswitch 70 acts as an on/off toggle to indicate occupancy or unoccupancyof a zone respectively. If an automatic time-out is required to returnthe zone to the unoccupied state, the period of time selected forautomatic time-out is large, preferably several hours in length.

The timed override switch 70 in conjunction with the setpoint 86C or 86Dcan also be used in servicing the system. By first setting the setpoint86C and 86D in an invalid state such as the extreme maximum or minimum,then touching the switch 70, the controller 68 can respectively beinstructed to enter a permanent override state or to open its damper 74to a maximum flow rate. A serviceman can then service the system in thatparticular state.

Although the controllers 68 are generally described herein ascontrolling the damper 74 of a terminal unit 48, the present inventionis not intended to be limited by the controller's application. Forinstance, the controller 68 could control the operation of the airhandler 50, or the water chiller 54 in response to data provided by thepresent invention. Additionally, the controller 68 can control othertypes of HVAC units (not shown) such as roof top air conditioning units,self-contained units, or packaged terminal air conditioners. Thecontroller 68 can also control the operation of the zone lighting 38,75to provide variable intensity lighting in response to user indicationsof lighting comfort levels, or in response to building managementcontrol strategies provided by the building automation system 76.

FIG. 24 shows a block diagram of a controller 68 including a TX1transceiver 400 for receiving and transmitting messages on the firstcommunications medium TX1. The transceiver 400 is connected to a messageencoder/decoder 402 which encodes or decodes messages received from orto be transmitted on the first communications medium TX1. Decodedmessages are supplied to a controller logic unit 404 which usesinformation from the messages in conjunction with control algorithms tocontrol a load 406 such as a damper 74, a variable speed fan, acompressor, an air conditioning unit, a light or lighting bank 38,75 orother similar devices. A memory 408 is provided and connected both tothe controller logic unit 404 and the message encoder/decoder 402 forstoring data, instructions and algorithms.

Each controller 68 attached to the bus 72 has the identification signal86A for the particular zone sensor 58 or zone sensors 58 located in thecontroller's zone 34 stored in the memory 408 of the controller 68. Thecontroller 68 monitors transmissions on the bus 72 for signals emanatingfrom that particular zone sensor 58 or zone sensor 58. Non-relevant datatransmissions are received and discarded. When the controller 68recognizes a data packet 86 from its designated zone sensor(s) 58, thecontroller 68 controls the position of a damper 74, or the speed of avariable speed fan (not shown), depending upon the mode of operation86E, the setpoint 86C, 86D, and the temperature 86B provided by the zonesensor 58. Although the present invention is described in connectionwith a controller 68 modulating zone temperature by modulating damperposition, other ways of modulating zone temperature are contemplatedincluding the use of variable speed primary air, return air and/ordischarge air fans or the use of a variable size orifice.

FIG. 3 shows a block diagram of the wireless communication system andthe air distribution system of the present invention. A firstcommunications medium TX1 such as the hard wired communications bus 72links a plurality of air handling controllers 68 to each other, to thecentral receiver 66, and optionally to a building automation system 76.The building automation system 76 allows the controllers 68 and zones 34to be centrally monitored and automatically coordinated. Each controller68 can exchange information via the first communications medium TX1.This first communications medium TX1 is implemented as thecommunications bus 72, which in the preferred embodiment is a twistedpair wire communications link transferring data in a serial fashion. Thefirst communications medium TX1 can also be implemented as a power linecarrier or the like.

Additionally, each controller 68 can receive setpoints and othercommands from the building automation system 76, and can transmit statusand other information to the building automation system 76. Commandsfrom the building automation system 76 can either be directed to aspecific controller 68, or can be in the form of a general broadcast toall controllers 68. Such a general system broadcast might provideoutside air temperature or might indicate that the power level of aparticular zone sensor 58 has depleted, and that controllers 68 relyingon information from that particular sensor should substitute a defaultsensor. In cases where it is not possible to substitute a default sensorbecause (1) a default sensor has not been designated, (2) the defaultsensor is known to be inoperative, (3) if the controller 68 is notconnected to the bus 72, or (4) the controller is being used as a standalone controller, the controller 68 operates using the last operatingmode and setpoints with which the controller 68 has been provided.

Referring to FIGS. 2 and 3, a source 78 of supply air from an airhandling unit 50 is provided by a supply air duct 80. A plurality ofbranch ducts 82 interconnect the supply air duct 80 to the plurality ofzones 34 whose environment is to be controlled. Each branch duct 82 hasa damper 74 or its equivalent controlled by the controller 68 of theparticular zone 34 or zones 34 to which the branch duct 82 suppliesconditioned air. Within each zone 34 is a zone sensor 58 which transmitsinformation to the central receiver 66 using a second communicationmedium TX2.

The second communication medium TX2 is preferably spread spectrum radiofrequency transmissions where the bandwidth of the transmitted signal isdeliberately widened to improve the signal to noise ratio. The use oftwo distinct redundant transmissions on two distinct frequencies is alsopreferred to insure that a message is received at its destination evenif one frequency is blocked. The use of spread spectrum radio frequencytransmissions, as opposed to other types of transmissions mediaincluding conventional radio frequency transmissions, is preferredbecause spread spectrum radio frequency transmissions have greaterrange, and are far less susceptible to interference from buildingstructures and electronic devices. In spread spectrum communications, aspreading algorithm is selected to spread the transmission over a muchgreater bandwidth than a conventional transmission bandwidth.Consequently, if the algorithm spreads the bandwidth of the transmission100 times as wide as the conventional bandwidth, a source ofinterference which interferes with 50% of a conventional bandwidth'stransmission will only interfere with 0.5% of the same transmission sentwith the spreading algorithm. Additionally, multiple spreadingalgorithms can be selected so that simultaneous transmissions usingdifferent spreading algorithms will, at most, minimally interfere witheach other. Spreading algorithms are described in Spread SpectrumSystems, Robert C. Dixon (2nd ed, 1984, John Wiley & Sons, Inc. NewYork, TK5102.5.D55, ISBN 0-471-88305-3) which is herein incorporated byreference. Although spread spectrum transmissions are preferred, thesecond communication medium TX2 can also be a conventional bandwidthradio frequency transmission, or in some limited circumstances thesecond communication medium TX2 can be an infrared or ultrasonictransmission.

As previously stated, the zone sensor 58 transmits a zone sensor datapacket 86 containing an identification code 86A, a zone mode ofoperation 86E, a heating or cooling zone setpoint 86C, 86D for thatparticular mode of operation, and a zone air temperature 86B, as well asbattery status 86F and timed override signals 86G. The central receiver66 receives the transmissions from each of a plurality of zone sensors58, checks to see if the transmission itself and the transmitting deviceare valid, formats each of the transmissions from the zone sensors 58into a format usable on the first communications medium TX1 andretransmits the zone sensor data packets 86 onto the firstcommunications medium TX1. Each of the plurality of controllers 68monitors the first communications medium TX1 for zone sensor datapackets 86 emanating from that particular controller's designated zonesensor 58 and controls a branch duct damper 74 in accordance with thosesignals.

FIG. 4 is a block diagram showing how the essentially hierarchicalwireless communication system of the present invention operates. Aplurality of air distribution controllers 68 are linked by the firstcommunications medium TX1 to at least one central receiver 66 capable ofreceiving transmissions on the second communication medium TX2. Thiscentral receiver 66 receives wireless transmissions on the secondcommunication medium TX2 from a plurality of zone sensors 58. These zonesensors 58 generally have a logical correspondence to the controllers 68although several controllers 68 can rely on information from the samezone sensor 58, or alternatively several zone sensors 58 can provideinformation to the same controller 68. These alternatives will besubsequently described.

The central receiver 66 receives the transmissions on the secondcommunication medium TX2, places the transmissions in the format of thefirst communications medium TX1, and retransmits the zone sensorinformation on the first communications medium TX1. The central receiver66 also maintains an internal list of valid zone sensors 58 for use inverifying the validity of data packet transmissions. These internallists are programmed by the building automation system 76 or the setuptool 320, and are an aid in reducing invalid or redundant transmissionson the first communications medium TX1. As previously stated, eachcontroller 68 recognizes identification codes 86A for particular zonesensors 58, extracts the information accompanying the identificationcode 86A, and uses that information to modulate airflow in a branch duct82 or in a zone air handling unit 84 such as an terminal air unit.

The zone 34 whose environment is to be controlled typically includes azone sensor 58, and a drop ceiling 88. Above the drop ceiling 88 is asupply air duct 80 supplying conditioned air from an air conditioningunit, a branch duct 82 connecting the supply air duct 80 to a terminalunit 84, and the terminal unit 84 which supplies the conditioned air tothe zone 34 to be controlled. A branch duct damper 74 controls the flowof conditioned air through the branch duct 82 from the supply duct 80 tothe terminal air unit 84. A controller 68 is operably connected to andin control of the branch duct damper 74. A first communications mediumTX1 such as the bus 72, using twisted pair, power line carrier, cable,or the like links the controller 68 to the central receiver 66, to othercontrollers 68, and to a building automation system 76 if provided. Thecontroller 68 controls the position of the branch damper 74, and therebyvolume of airflow to the zone 34, in response to information receivedfrom the zone sensor 58 over the first communications medium TX1. Unlikeconventional approaches, the zone sensor 58 of the present invention hasno physical connection to the controller 68. Instead, the zone sensor 58communicates information in the general form of the data packet 86 tothe central receiver 66 using a wireless second communication medium TX2such as spread spectrum radio frequency transmissions. The centralreceiver 66 is operably connected to the first communications medium TX1and retransmits the zone sensor data packet 86 onto the firstcommunications medium where the controllers 68 can access theinformation in the zone sensor data packet 86.

FIG. 5 is an example of the present invention applied to a pair ofdistinct buildings 90, 92. One building 90 has a first floor 94 havingtwo zones Z1, Z2, and a second floor 96 having three zones Z3, Z4, Z5.The single story building 92 has an interior 98 which has been dividedinto three zones Z6, Z7, Z8. Each zone Z1 through Z8 has a controller 68controlling a supply of conditioned air to the particular zone Z1through Z8. For simplicities sake, the dampers, the duct systems, theair handling systems, and the air conditioning systems are not shown,but can be seen in reference to FIGS. 1 through 4.

In FIG. 5 there is one controller 68 for each zone Z1 through Z8, andeach controller 68 is interconnected by the first communications mediumTX1, e.g. the communications bus 72. The bus 72 is also connected to asingle central receiver 66. Each zone Z1 through Z8 has a single zonesensor which, for the sake of simplifying this example, is alsoidentified as Z1 through Z8. Each zone sensor Z1 through Z8 monitorsenvironmental conditions and periodically, for instance at five minuteintervals, transmits a data packet 86 similar to that shown in FIG. 6 tothe central receiver 66 by means of the second communication medium TX2.The second communication medium TX2 is preferably spread spectrum radiofrequency transmissions. The zone sensors Z1 through Z8 also transmit onevery change of state or whenever a user command is entered. The centralreceiver 66 receives each transmission, reformats the transmission intothe format required by the first communications medium TX1 andretransmits the reformatted information on the first communicationsmedium TX1. Each controller 68 monitors the transmissions on the firstcommunications medium TX1 and extracts and uses data from apre-identified zone sensor or zone sensors Z1 through Z8. Eachcontroller 68 may also respond to a general system broadcast on thefirst communications medium TX1 indicating, for instance, that a firehas been detected and appropriate measures should be taken.

As an example of the transfer of a data packet 86 from a zone sensor 68to a controller 68, zone sensor Z6 transmits a data packet 86 containinga zone sensor identification code 86A, zone air temperature 86B andother information to the central receiver 66. This information isretransmitted over the communications bus 72, identified by a particularcontroller 68Z, and used to regulate the flow of conditioned air to thezone Z6. If the air temperature 86B is above the cooling setpoint 86D ofthe zone Z6, and the zone Z6 is in the cooling mode 86E, the controller68Z will provide increased flow of cooled air to the zone Z6. If the airdistribution system 32 is a changeover system which is currentlyproviding heated air, the controller 68Z will call for cooling to thebuilding automation system 76 or to the water chiller 54. The controller68Z will then act to minimize the amount of heated air allowed into thezone Z6.

The controller 68Z preferably includes means for maintaining the bestavailable mode of operation in the event that the designated zone sensorZ6, the primary preferred sensor, should fail. For example, if thecontroller 68Z does not receive information from its designated primaryzone sensor Z6 within a predetermined time frame, such as a five or tenminute period, the controller 68Z monitors transmissions from asecondary zone sensor if available. In this case, the zone sensor Z7 canfunction as a secondary zone sensor because the zone sensor Z7 is withinthe same physical space, i.e. the interior 98, and because thecontroller 68Z has previously been programmed by a building automationsystem 76 or a setup tool 320 to recognize Z7 as a secondary zonesensor. This has the advantage that the controller 68Z can continue tooperate with actual feedback from the building interior 98 rather thanshutting down or controlling airflow based upon some programmed defaultmode which has no temperature feedback. Furthermore, should thesecondary zone sensor Z7 fail, the controller 68Z can recognize the zonesensor Z8 as a tertiary source of information, and continue to supplyconditioned air to the zone Z6 using information supplied from the zonesensor Z8. Only when the primary sensor and all designated alternatesensors fail will it be necessary to shutdown or operate in apreprogrammed default mode of operation. Such a preprogrammed mode ofoperation might compare default setpoints to supply air temperature asmeasured by a supply air temperature sensor (not shown) hard wired tothe first communications medium TX1, or, in a retrofit environment,might continue to operate using information provided by hard wired zonesensors if any such zone sensors remain attached to the system.

FIG. 7 shows the structure of the present invention where a coordinatingcontroller 102 has been added to the hierarchical control system shownin FIG. 4. A coordinating controller 102 communicates with each of thecontrollers 68 by means of the communications bus 72, and coordinatesthe activities of those controllers 68. The coordinating controller 102receives operating information such as damper position and zonetemperature from the controller 68 and transmits command informationsuch as setpoints and open/close commands to the controllers 68. Thecoordinating controller 102 facilitates building monitoring andscheduling on a smaller scale than a building automation system 76, andin fact can comprise an element of a building automation system 76. Boththe coordinating controller 102 and the building automation system 76include a broadcast function allowing the transmission of system widecommands and data. Examples of the broadcast function include theperiodic broadcast of the outside air temperature to all controllers 68,and the broadcast of a command to instruct all controllers 68, or agroup of controllers 68, to commence air balancing.

Second Embodiment

FIG. 8 illustrates the hierarchical structure of a second preferredembodiment of the present invention. The second embodiment adds a thirdcommunication medium TX3 transmitting personal comfort information froma plurality of personal comfort sensors 110. In this embodiment, thecontrollers 68 communicate, as before, by means of the firstcommunications medium TX1, i.e. the communications bus 72. A pluralityof zone sensors 58 transmit zone information to the central receiver 66using a second communication medium TX2 such as spread spectrum radiofrequency transmissions. The central receiver 66 reformats thetransmissions from the zone sensors 58 and retransmits the zoneinformation on the first communications medium TX1 for use by the zonecontrollers 68.

FIG. 22 shows a block diagram of a personal comfort sensor 110. Thepersonal comfort sensor 110 includes a housing 340 which includes amicroprocessor controller 342; a TX3 output device 344 such as a wiredconnector 344D, an infrared transmitter 344B, a radio transmitter 344Aor a spread spectrum RF transmitter 344C; and a power source 346 such asa battery. A battery monitor 348 is provided to monitor the level of thepower source 346 if the power source 346 is depletable. Additionally andas described in connection with the zone sensor 58, the personal comfortdevice 110 is provided with the capability to enter a dormant, powersaving state if the power supply 346 is depletable. The personal comfortsensor 110 also includes various inputs to the microprocessor controller342 such as a timed override input 350, an air temperature input 352, anair flow input 354, a lighting comfort level input 355, an air qualityinput 356, a comfort indication input 358 and a generic sensor input359. The personal comfort sensors 110 each monitor the conditions withina localized region and transmit the monitored information in a personalcomfort data packets 100 to predetermined zone sensors 58. Thepredetermined zone sensors 58 then retransmit the personal comfortinformation to the central receiver 66 either as a separate data packeton the second communication medium TX2, or incorporate the personalcomfort information into the zone sensor data packet and send a singletransmission for subsequent retransmission on the first communicationsmedium TX1.

For instance, the zone sensor 58 identified as Z10 in FIG. 8 receives atransmission from the personal comfort sensor 110a on the thirdcommunication medium TX3 and retransmits the information to the centralreceiver 66 on the second communication medium TX2 for subsequentretransmission on the first communications medium TX1. The zone sensor58 identified as Z11 receives transmissions from the personal comfortsensors 110b and 110c on the third communication medium TX3, retransmitsthe personal comfort information on the second communication medium TX2to the central receiver 66, which subsequently retransmits theinformation on the first communications medium TX1. The zone sensor 58identified as the Z12 receives transmissions from the personal comfortsensors 110d, 110e, and 110f by means of the third communication mediumTX3, and retransmits those personal comfort information packets to thecentral receiver on the second communication medium TX2, for subsequentretransmission on the first communications medium TX1. The use of athird communication medium TX3 prevents the central receiver 66 frombeing overloaded with incoming transmissions, while facilitating thegrouping of sensors in logical arrangements.

The third communication medium TX3 is preferably a wirelesscommunications medium distinct from the second communication medium TX2so that the third and second communication mediums TX3,TX2 do notinterfere with each other's transmissions. For instance, if the secondcommunication medium TX2 is spread spectrum radio frequency, the thirdcommunication medium TX3 is preferably infrared, ultrasonic, or narrowband radio frequency transmissions. The third communication medium TX3can also be a hard wired connection between the personal comfort sensor110 and the zone sensor 58 such as a cable, a twisted pair link, or anoptic fiber link. Alternatively, the third communications medium TX3 canbe the same communications medium as the second communications mediumTX2, if the two media are readily distinguishable, such as, for example,by the use of distinct frequencies. Alternatively, distinct,non-interfering spreading algorithms could be employed by the second andthird communications media TX2, TX3.

FIG. 9 shows a personal comfort data packet 100 for transmission by apersonal comfort sensor 110. That data packet 100 includes a personalcomfort identification code 100A, air temperature 100B, air flow 100C,air quality 100D, a personal comfort indicator 100D that the user iseither too warm or too cold, a battery status 100F, the initiation oftimed override 100G by a user, and a lighting comfort level indication100H that zone lighting is too dim or too bright. Preferably thepersonal comfort data packet 100 is prefixed by a message type 100T.Additionally, the personal comfort sensor 110 can include anaccompanying generic sensor input 359 which allows, for example, ahumidity sensor (not shown) to be connected to a personal comfort sensor110 and to forward humidity data 100I. At different times, other sensorscan also be connected to the generic sensor input 359 such as anoccupancy sensor. In this case, the personal comfort data packet 100indicates the occupied/unoccupied status 110i of the area beingmonitored by the occupancy sensor.

FIG. 2 shows a personal comfort sensor 110 transmitting this informationby infrared transmission on the third communication medium TX3 to aninfrared receiver 112 included in the zone sensor 58. The zone sensor 58receives the transmission of a personal comfort data packet 100 from thepersonal comfort sensor 110 and appends the personal comfort sensor datapacket 100 to the zone sensor's data packet 86. This is subsequentlydiscussed with regard to FIG. 13. A single transmission is then made tothe central receiver 66 by the zone sensor 58 on the secondcommunication medium TX2. The central receiver 66 then either places thezone sensor transmission on the first communications medium TX1unaltered, or separates the zone sensor data packet 86 and the personalcomfort data packet 100 from each other and transmits each on the firstcommunications medium TX1 independently.

The personal comfort sensor 110 shown in FIG. 2 also includes a comfortindication input 358 such as a comfort indicator switch 114 having aneutral position, a warmed air request position and a cooled air requestposition which a user can use to indicate that the user is too warm, ortoo cold. The user's indication is incorporated into the personalcomfort sensor data packet 100 as the comfort indicator 100E andtransmitted to the relevant zone sensor 58. Although the comfortindicator switch 110 is described as having a neutral position, a warmedair request position, and a cooled air request position, the comfortindicator switch 110 can have further positions such as energyefficiency.

The information provided by the personal comfort sensors 110 generallyrelates to system controllable elements such as zone air temperature,zone air quality, zone air flow, and zone energy efficiency. Zone energyefficiency is an optional user input which allows the user to indicateto the controller 68 that the user is more interested in energyefficiency and energy conservation than in personal comfort and that thecontroller 68 can shift the boundaries of comfort control in an energyefficient or energy conserving manner. Energy efficiency allows a userto tell the zone controller 68 that the user is more interested inenergy efficiency and in energy conservation than in the user's personalcomfort. The controller 68 is then authorized to automatically vary thecooling setpoint, the heating setpoint, and the mode of operation so asto condition the zone in the most energy efficient manner. For instance,when operating in an energy efficient mode on a cool day, the heatingsetpoint might be automatically lowered 2° F. so that the heating systemoperates less often. Similarly, on a warm day the cooling setpoint mightbe automatically raised 3° F. so that the cooling system operates lessoften.

The personal comfort sensor 110 also includes a lighting comfort levelinput 100I which allows a user to indicate that lighting 38,75 is toobright, too dim, or should undergo a change of state from off-to-on, oron-to-off. The controller 68 receives the lighting comfort level input100H and controls the zone lighting system 75 accordingly.

FIG. 10 illustrates an example of the second preferred embodiment. Abuilding 118 having a first floor 120 and a second floor 122 is dividedinto three zones 124, 126, 128, each zone 124, 126, 128 having a zonesensor 58 respectively designated Z13, Z14, Z15. In this case, eachfloor 120, 122 is provided with a central receiver 66, which might benecessary if the material 121 separating the floors 120, 122significantly impedes the transmissions on the second communicationsmedium TX2. The central receiver 66 on the second floor 122 receivesdata packets 86, 100 transmitted from the zone sensor Z13 and thepersonal comfort sensors 110g, 110h, 110i, and 110j; and retransmits thedata packets 86, 100 on the first communications medium TX1 for use bythe controllers 68a, 68b. The central receiver 66 on the first floor 120receives data packets 86, 100 transmitted from the zone sensors Z14, Z15and the personal comfort sensors 110k, 110L and retransmits the datapackets 86, 100 on the first communications medium TX1 for use by thecontrollers 68c, 68d, 68e. The situation where a central receiver 66receives a zone data packet 86 through the flooring material 121 andretransmits the zone data packet 86 intended for the central receiver 66of another floor is not a problem. This is because a controller 68 willmerely be instructed to perform the same operation twice.

The zone sensor Z13 transmits zone sensor information for use bycontroller 68a and 68b, the zone sensor Z14 transmits information foruse by the controller 68c, and the zone sensor Z15 transmits informationfor use by the controllers 68d and 68e. The zone 124 might be an officearea having half walls 130 separating individual office areas 132. In asituation where the sun heats a first end 134 of the zone 124, and thewind cools a second end 136 of the zone 124, the placement of a singlezone sensor Z13 might be impossible to provide uniform air temperaturethroughout the zone 124. However, using the second embodiment of thepresent invention, some or all of the individuals areas 132 can beprovided with personal comfort sensors 110, preferably fixed in placeunlike the personal comfort sensor of FIG. 2.

Each personal comfort sensor 110 transmits personal comfort informationto the zone sensor Z13 by means of the third communication medium TX3.The zone sensor Z13 transmits all of the information from the zone 124to the central receiver 66, including the zone sensor's own informationas well as the personal comfort sensor information. The central receiver66 then transmits the zone information on the first communicationsmedium TX1 where the information is received by the controller 68a and68b. Controller 68a preferably controls the environment in the zone 124using the temperature information provided by the personal comfortsensor 110g, the personal comfort sensor 110h and the zone sensor Z13.The controller 68b preferably controls the environment of the zone 124using temperature information provided by the personal comfort sensor110i, the personal comfort sensor 110j, and the zone sensor Z13. Thezone 126 is controlled solely in response to zone sensor Z14, while thecontrollers 68d and 68e control the zone 128 by averaging the airtemperatures reported by the zone sensor Z15 and the personal comfortsensors 110k and 110L.

A number of approaches, some of which are discussed in connection withFIG. 14, can be used to allow the controllers 68 to control theenvironment using multiple sensors. These approaches include averagingthe air temperature received from each of these sensors, weighting theair temperatures and/or setpoints received from the sensors, selectingmode of operation in accordance with the mode requested by a majority ofsensors, or controlling the environment to minimize the largestdeviation from setpoint of any one of the sensors.

Third Embodiment

FIG. 11 shows the hierarchical structure of a third embodiment of thepresent invention. In the third embodiment, the zone sensors 68 and thepersonal comfort sensors 110 can each transmit on either the thirdcommunication medium TX3 or on the second communication medium TX2. Foreconomic reasons and for the sake of simplicity, it is preferable thatthe zone sensors 68 and the personal comfort sensors 110 be providedwith the capability to transmit on either one or the other of the secondor third communications media TX2, TX3 and not on both media. Thisselection is expected to be made by the system designer.

In FIG. 11, three zone sensors 138 and two personal comfort sensors 140transmit zone data packets 86 to the central receiver 66 on the secondcommunication medium TX2. A personal comfort sensor 142 also transmitsdata on the third communication medium TX3 to zone sensor 138a forincorporation into the zone data packet 86 of zone sensor 138a andsubsequent retransmission to the central receiver 66. Two additionalpersonal comfort sensors 144a and 144b transmit data to the zone sensor138b by means of the third communication medium TX3 for subsequentretransmission to the central receiver 66 on the second communicationmedium TX2. The central receiver 66 reformats the zone data packets 86and retransmits those zone data packets on the first communicationsmedium TX1 where the zone data packets 86 can be accessed by thecontrollers 68.

The third embodiment has the advantage that airflow and other datasensed by the personal comfort sensors 110 can be supplied to thecontrollers 68 without the necessity of implementing a thirdcommunication medium TX3. Additionally, the interchangeability of thezone sensors 58 and the personal comfort sensors 110 provides greateruser flexibility in designing economical and efficient air distributionsystems, particularly where there is a cost disparity between either thepersonal comfort sensors 110 and the zone sensors 58, or between thesecond communication medium TX2 and the third communication medium TX3.If desired, a zone sensor 58 can be used transmitting on the thirdcommunication medium TX3.

FIG. 12 is an example of the third embodiment of the present inventionas applied to a two story building 146. The two story building 146 hastwo floors 148 and 150, the first floor 148 of which includes two largeareas 152 and 154. The large area 154 is a single zone controlled by asingle controller 156 and a single zone sensor 158. The other large area152 is serviced by two controllers 160 and 162. The controller 160receives zone data packets 86 from a zone sensor 164 and a personalcomfort sensor 166 connected to the zone sensor 164 by a cable type link168 which implements a third communication medium TX3. The controller162 is supplied with zone sensor data packets 86 by a zone sensor 170and a personal comfort sensor 172. The zone sensor 170 is provided withdata from the personal comfort sensor 172 over a fiber optic link 174which implements the third communication medium TX3.

The second story 150 of the building 146 includes offices 176 separatedby half walls 178. Each office 176 includes a portable personal comfortsensor 180 which transmits zone data packets 86 over the secondcommunication medium TX2 to the central receiver 66 for subsequentretransmission on the first communications medium TX1 to the controller68.

FIG. 12 also illustrates the use of redundant central receivers 66,where each floor 148, 150 is provided with a pair of identical centralreceivers 66. Each of the central receivers 66 is expected to act as abackup to the other central receiver 66. Consequently, each centralreceiver 66 is constantly retransmitting all transmissions received onthe second communications medium TX2. Effectively, while both centralreceivers 66 are operative, each zone data packet 86 is receivedredundantly by the relevant controller 68. If the redundanttransmissions by the redundant receivers 66 begins to degrade the firstcommunications medium TX1, it is preferable to modify the data fileswithin the memory 364 so that a minimum time between transmissions toany particular controller 68 is formed. This minimum time limit ismathematically determined to minimize collisions on the firstcommunications medium TX1, and could be on the order of 30 seconds.Alternatively, to reduce transmissions on the first communicationsmedium TX1, the redundant central receiver 66 can be instructed tooperate normally with the exception that no transmissions on the firstcommunications medium TX1 are made unless an "active" central receiver66 fails to transmit an expected data packet 86, 100 or command within apreset time period. The execution of duplicate instruction or theresponse to duplicate data packets 86 by the zone controllers isimmaterial because the instructions and the redundant zone data packets86 are identical.

FIG. 13 shows a zone data packet 86 such as might be sent by the zonesensor 138b of FIG. 11 and includes the data from the personal comfortsensors 144a and 144b. For simplicity of transmission, in the preferredembodiment all transmissions on the second communication medium TX2 areof the same fixed length, thus enabling the central receiver 66 toreadily recognize complete data transmissions. The data packet 86includes three sections 182, 184, 186 respectively directed to the datafrom the zone sensor 138b, the personal comfort sensor 144a and thepersonal comfort sensor 144b. Each section 182, 184, 186 is preferablypreceded by a message type respectively 182T, 184T, 186T. The zonesensor section 182 includes a zone sensor code 190, zone air temperature192, heating setpoint 194, cooling setpoint 196, mode of operation 198,battery status 200, and timed override status 202, for the zone sensor138b. The data packet 86 also includes the data section 184 from thepersonal comfort sensor 144a including the personal comfort sensoridentification code 206, personal comfort sensor air temperature 208,airflow 210, air quality 212, user's lighting comfort level 213, user'scomfort indicator 214, battery status 216, and timed override 218. Thethird section 186 of the data packet 86 is the data associated with thepersonal comfort sensor 144b including the personal comfort sensoridentification code 220, air temperature 222, airflow 224, air quality226, user's lighting comfort level 227, user comfort indicator 228,battery status 230, and timed override 232.

Each zone sensor in the system shown in FIG. 11 will transmit a datapacket of this length. In the case such as the zone sensor 138a and thepersonal comfort sensor 142, the section 186 will be blank as a secondpersonal comfort sensor does not report to the zone sensor 138a. In thecase of the zone sensor 138c, both the sections 184, 186 will be blankas no personal comfort sensor reports to the zone sensor 138c. Finally,in the case such as personal comfort sensor 140, the sections 182, 186will be left blank as no zone sensor or second personal comfort sensoris present. In this last case, the personal sensor identification code206 of the personal comfort sensor 140 might be copied to the zonesensor identification code 190 for ease of identification by thecontrollers 68. The use of fixed length transmissions enables thecentral receiver 66 to recognize the completeness of the data packet 86,and reformat and retransmit the data packet on the first communicationsmedium TX1. A specific controller 68b is able to monitor the firstcommunications medium TX1 for data packets 86 having the identificationcode for zone sensor 138b, personal comfort sensor 144a, and/or personalcomfort sensor 144b. However, it should be recognized that the presentinvention need not be implemented using a single fixed length datapacket. For instance, variable length data packets identified withstop/start identifiers could be implemented, or each sensor couldtransmit an independent and unique data packet.

Operation

FIG. 14 is a flow chart showing the operation of a controller 68 beingprovided with data from a multiplicity of zone and personal comfortsensors 58, 110. The operation is shown by flow chart 236 where, afteran initialization step 238, the controller 68 enters an endless loop240. At step 242 the controller 68 constantly monitors the firstcommunications medium TX1 for activity, and determines if that activityis either a command from a building automation system 76 or a setup tool320, or a zone data packet 86 from one of a plurality of predesignatedzone sensors 58 and personal comfort sensors 110. The message type 86T,100T, 182T, 184T, 186T and 104A prefixed to each data or command packetfacilitates this determination.

Each time a relevant data packet 86 is received, data files associatedwith the particular zone sensor 58 or personal comfort sensor 110 areupdated, and associated timers are reset. These timers or theirequivalent are important to this system because the transmissions fromzone sensor 58 to the controller 68 are essentially one way, and thecontroller 68 needs some means for determining when sensor failure ortransmission medium failure has occurred. A fairly simple means of doingthis is accumulating the elapsed time since the last valid sensor datatransmission. An alternative approach is to compare the newest sensordata with the previous sensor data and determine if any deviationbetween the old and new data is reasonable in view of the timedifference between the receipt of the old and new sensor data.

At step 244 the controller 68 determines if activity on the firstcommunications medium TX1 is a valid command from a building automationsystem 76 or a setup tool 320, and if so, executes the command andrecommences monitoring the first communications medium. If the activityon the first communications medium TX1 is information in the form of azone sensor data packet 86, or if a predetermined time period (such asfive minutes) has passed since activity has been detected on the firstcommunications medium TX1, the controller 68 decides that a failure hasoccurred and determines which alternate zone sensor data should be usedso as to maintain the best available mode of operation. In flow chart236 each primary sensor has an alternate secondary sensor, and analternate tertiary sensor. For the sake of illustration, zone sensorsZ6, Z7 and Z8 from FIG. 5 are respective examples of a primary,secondary and tertiary zone sensor. At step 248 a timer for the primarysensor Z6, the sensor whose data should be used as the basis forcontrolling the zone environment, is checked to see if the timerindicates a failure by the sensor to provide data within thepredetermined time period. If the timer has not expired, the data fromthe primary sensor Z6 is used. If the primary sensor Z6 has failed toprovide recent data, the controller 68 at step 252 attempts tosubstitute a predesignated secondary sensor Z7 for the primary sensorZ6. This secondary sensor Z7 might be a personal comfort sensor 110 ormight be the zone sensor 58 of an adjacent or similar zone. A timer canalso be associated with the secondary sensor, and if the secondarysensor Z7 has provided recent data, that data is used at step 254. Ifthe secondary sensor Z7 has failed to provide data within apredetermined time period, then a tertiary sensor Z8 might besubstituted at steps 256 and 258 if the tertiary sensor Z8 has notfailed. If all designated sensors have failed or if no sensor hasprovided fresh data, which might occur in the event of a component orpartial system failure, the controller 68 operates using predefineddefault parameters at step 260. These predefined default parametersmight be a preset mode of operation, i.e. minimum damper position, ormight instruct the controller 68 to use the last valid data packet 86from the primary sensor Z6 as a basis for modulating zone temperature.Alternatively, the controller 68 can either be instructed to supply airto the zone 34 using default setpoints and hard wired sensors such assupply air temperature sensors, or the controller 68 can be instructedto terminate operations.

Once the controller 68 has established which sensor's data is to berelied upon in operation, the controller 68 selects a mode of operation.In the case of a system where a single sensor is associated with asingle controller 68, the mode of operation is the mode 86E designatedin that particular zone sensors data packet 86. At step 262 thecontroller 68 determines if such a single sensor system is being usedand, if so, uses the mode 86E and data at step 264 from that sensor'sdata packet 86.

However, in a multi-sensor system such as that shown in FIG. 15, thecontroller 68 must determine how to use the data provided. In FIG. 15three zone sensors 268, 270, and 272 provide information to a singlecontroller 68Y. Several options are available to the controller 68 oncea multi-sensor system has been recognized at step 262. For instance,step 274 shows a voting arrangement where the mode of operation isselected based upon the modes requested in the zone sensor data packets86 by the majority of sensors 268, 270, 272 at step 276. If no majorityexists, the mode of operation is selected at 278 using the moderequested by the sensor with the largest deviation from setpoint. If nosuch sensor exists, the existing mode is continued at step 282.

Once the mode of operation is selected, the damper 74 is controlled atstep 284 using either a temperature average from all designated sensorsas compared to a master setpoint, or by using a representative sensor.The master setpoint can be explicitly designated, or can be implicitlydesignated by its order in the controller's data structure.Additionally, either the sensor temperature data or the zone setpointcan be determined using a weighted average. For example, in a threesensor system two peripheral sensors might have their setpoint andtemperature information weighted at 30% each while a centered sensormight have its setpoint and temperature data weighted at 40%.

As an alternative to controlling the damper 74 at step 284, the speed ofa variable speed fan (not shown) in a terminal unit 48 might becontrolled. Regarding system initialization, a building automationsystem 76 or a setup tool 320 is used to initially convey the selectionof the zone sensor system to the controller's 68, and to subsequentlyalter any parameters. In the event of a conflict between the buildingautomation system 76 and the setup tool 320, the building automationsystem 76 will override the setup tool 320.

FIG. 16 shows the operation of the central receiver 66 in the form of aflow chart 286. The flow chart 286 begins with an initialization routineat step 288 and then constantly monitors the second communication mediumTX2 at step 290. Messages such as data packets 86,100 or commandsreceived on the second communication medium TX2 are checked for validityat step 292. If the message is valid at step 292, the message type 104A,86T, 100T, 182T is checked to see if the message is a setup command atstep 298. If so, an audible tone is sounded at step 299 and the messagedata is added to the internal list. The validity of the messagetransmitter itself is checked against an internal list of validtransmitters at step 296. The message is reformatted at step 294 intothe data format used on the first communications medium TX1 andtransmitted on the first communications medium TX1 at step 300. Althoughthe present invention is disclosed in terms of reformatting the datafrom the second communication medium to the format used in the firstcommunications medium TX1, it should be recognized that these dataformats could be similar and the reformatting step omitted.

FIG. 17 is a flow chart 302 showing the operation of a typical zone orpersonal comfort sensor 58, 110. After beginning the flow chart 302 atstep 304 with an initialization routine, the zone or personal comfortsensor 58, 110 is activated or awakened from a dormant state at step 305by either (1) a hardware timed interrupt on the order of every twoseconds, (2) the receipt of a personal comfort data packet 100 from apersonal comfort sensor 110, (3) a change of state such as an input fromthe timed override switch 70, the setpoint device 60, or the mode ofoperation selector 62, or (4) the receipt of a command data packet 104from a setup tool 320. The zone or personal comfort sensor 58, 110 thenmonitors the environment of the zone 34 at step 306 by sampling andfiltering the temperature 64, by sampling the timed override switch 70and the mode of operation switch 62, and by sampling a setpoint wheel60. A software timer is periodically checked at step 308 to ensure thatthe zone or personal comfort sensor 58, 110 sends data no more oftenthan 30 seconds but at least every five minutes, whether or not a changeof state has occurred. Additionally, any time a change of state occursor a command or data packet 104,100 has been received, data istransmitted at steps 310 and 312. At step 314 the zone sensor 58determines if a command data packet 104 has been received either by aphysical connection 316 or by the third communications medium TX3. If acommand data packet 104 has been received, and at least 30 seconds haselapsed since the last transmission, the data packet 104 is transmittedat step 312, otherwise the zone or personal comfort sensor 58, 110 goesto sleep at step 315. Going "dormant" is a method of conserving anon-renewable power source 59 such as a battery 59. If the power source59 is continually renewed, it is not necessary to render the zone sensor58 or personal comfort sensor 110 dormant. Each time data istransmitted, the software timer accumulating time since the lasttransmission is reset. Depending upon which embodiment of the presentinvention is being implemented, the zone or personal comfort sensor 58,110 can transmit data at step 312 on either the second communicationmedium TX2, or the third communication medium TX3. Monitoring is thenrecommenced at step 306.

FIG. 18 shows a command data packet 104 containing a message type 104A,the controller identification code 104B of the controller 68 to whichthe command data packet 104 is being directed to, a zone identifier 104Cidentifying a particular zone 34 being assigned to the controller 68,designated by the controller identificator code 104B, and instructions104D as to whether to add or subtract the zone 34 to or from thecontroller's memory 408. Additional commands can indicate that thecontroller's memory 408 should be purged 104E of zone assignments anddata; that the data from the zone 34 be averaged 104F with otherassigned zones 34; or the data from the zone 34 be used as a secondaryor tertiary backup sensor.

Also commands can indicate, as subsequently discussed, that the zonesetpoint 86C or 86D be used as a master setpoint 104G for comparisonwith averaged or weighted temperature information from a plurality ofzones 34. A master setpoint 104G can be a 1 bit designation or, ifsetpoints are weighted by percentage between a number of zone sensors58, the designation can be a weighted percentage of 100%. For example,in a three sensor zone, such as zone 128 of FIG. 10, having two interiorsensors Z15,110k and one peripheral sensor 100L, the peripheral sensor100L might be weighted 40% and the interior sensors Z15, 110k weighted30% each. The controller 58 averages the temperature data from the threesensors, and compares that average to a setpoint determined from 40% ofthe peripheral zone setpoint 110L and 30% of each of the interior zonesetpoints Z15,110k. However, if the peripheral zone sensor 110L was themaster setpoint, the peripheral zone sensor 110L would be weighted 100%and the interior zone sensors Z15,110k each be weighted 0 %.

Setup Tool

The controllers 68 receives their initial and subsequent programming andcommands from either a building automation system 76, a coordinatingcontroller 102, or a setup tool 320 by means of the first communicationmedium TX1.

In the case of the setup tool 320 shown in FIGS. 19 and 20, the setuptool 320 uses a non-physical link such as the second communicationmedium TX2 and possibly the third communications medium TX3 to provideprogramming, information or commands to any particular controller 68 bymeans of the central receiver 66. For instance, the setup tool 320 canbe provided with a transmitter 322 so that programming instructions canbe directly transmitted on the second communications medium TX2 to thecentral receiver 66 and thereafter to the controller 68. The setup tool320 can also, or alternatively, be provided with a wired connector suchas an electrical plug 324 capable of operatively interfacing with amating connection 316 on a zone sensor 58 or a personal comfort sensor110. The setup tool 320 programming instructions are then indirectlytransmitted by the zone sensor 58 to the central receiver 66 forsubsequent retransmission to the controller 68. The setup tool's mayalso directly or indirectly transmit programming instructions on thethird communications medium TX3 using an infrared transmitter 326 or theelectrical connection 324 to a personal comfort sensor 110,respectively.

The setup tool 320 typically includes a housing 328 containing amicroprocessor controller 330; and output device 332 such as a radiotransmitter 322, a wired connector 324, or an infrared transmitter 326;a power source 334 such as a battery or a household AC plug connector; akeyboard 336; a display 338; a number of input switches 104D, 104E and104F; a power indicator 335; a transmit indicator 337; and a genericsensor input 104H. The generic sensor input 104H (subsequentlydiscussed) allows a humidity or temperature sensor to be attached to thesetup tool 320 and provide a sensed signal value for transmissionthrough the hierarchical communications system. Additionally, the wiredconnector 324 may be designed to provide power from the setup tool 320to a zone sensor 58 or a personal comfort sensor 110. Conversely, thesetup tool 320 may parasitically draw power from a zone sensor 58 or apersonal comfort sensor 110 or use the transmitter of a zone sensor 58or a personal comfort sensor 110 by way of the wired connector 324.

The keyboard 336 and display 338 allow a user of the microprocessorcontroller 330 to construct program instructions and commands andtransmit these programmed instructions as data packets 104. Thetransmissions may be directly on the second communications medium TX2 tothe central receiver or indirectly on the third communications mediumTX3 to the central receiver 66 by means of a zone sensor 58.

Commands from the setup tool 320 are transmitted in the same formatshown in FIGS. 6, 9, and 13 and described in connection with FIGS. 7 and18, except that the message type 104T is varied to indicate that acommand packet 104 as opposed to a sensor data 86 is being transmittedto a particular controller 68. The message type also tells thecontroller 68 to look for the controller's own identification designatorat the location 104B in the command data packet 104 instead of lookingfor the zone sensor identification code 86A.

When the central receiver 66 accepts a command from the setup tool 320,an audible signal is sounded by the audible annunciator 365. Thisprovides an acknowledgement to the user of the setup tool 320 that thecommand has been received. It is highly advantageous to receive thisacknowledgement in a one-way communication system such as that of thepresent invention. If desirable the audible tones may be coded or variedto indicate various responses to the command.

Generic Sensor Input

The present invention also contemplates a generic sensor inputconnection 49, 104H, 359 respectively associated with the zone sensor58, the personal comfort sensor 110, and the setup tool 320. The genericsensor input 49, 104H, 359 allows an external device (not shown) such asa humidity or occupancy sensor to be attached to the zone sensor 58, thepersonal comfort sensor 110, or the setup tool 320. The zone sensor 58,the personal comfort sensor 110, or the setup tool 320 recognizes theattachment of a generic sensor to the generic sensor input 49, 104H,359, identifies the type of generic sensor, and thereafter uses thegeneric sensor in a conventional manner. Numerous advantages areprovided in the areas of system flexibility, as well as in systemcalibration and system problem diagnosis. Furthermore, the genericsensor input 49, 104H, 359 can also be used as an external power supplyattachment for a zone sensor 58, a personal comfort sensor 110, or asetup tool 320 in need of additional or supplemental power. The genericsensor input 49, 104H may also be used as the interface 316 which allowsa setup tool 320 having a connector 324 to plug that connector 324 intoa zone sensor 58 or a personal comfort sensor 110. Conceivably, powermay be provided to the setup tool 320 from the zone sensor 58 or thepersonal comfort sensor 110 by means of the generic sensor input 249,104H.

Air Balancing

Customized air balancing is also contemplated by the present invention.Balancing is advantageous for two situations. Firstly, system balancingis required to balance the central air conditioning plant against thebranches 82 to ensure that the HVAC system is capable of providingdesign airflows to all system components under maximum airflowconditions. Secondly, zone balancing is required to satisfy specificzone operating conditions such as the elimination of eddy ortornado-like effects in hallways, and the elimination or modification ofextreme pressure zones.

When an air distribution system is installed, the entire airdistribution system goes through an initial system balancing. Referringto FIGS. 2 and 3, balancing dampers 350 in the branch duct lines 82, andair flow meters 352 also in the branch duct lines 82, are used tobalance the flow of air throughout the system. This is typically aniterative process wherein an air flow setpoint for each branch duct line82 is determined by a system designer, and the balancing damper 350 ineach duct 82 throughout the system is iteratively adjusted until alldesign airflow requirements are reached.

In the present invention the iterative process can be substantiallyeliminated by causing the building automation system 76 tosimultaneously initiate balancing throughout the system. Each controller68 is provided with an airflow setpoint, and when the signal from thebuilding automation system 76 is received on the first communicationsmedium TX1, the controller 68 begins to adjust its balancing damper 350while comparing measured airflow from the air flow sensor 253 to theairflow setpoint. Since all the controllers 68 in the system are doingthis simultaneously, air balancing can be quickly accomplished.

Additionally, the present invention facilitates rebalancing zones andlocalized portions of the air distribution system. Often the designairflow setpoint is subsequently found to be inadequate to meet theneeds of a particular zone or group of zones. This may occur becausepressure gradients cause too much or too little airflow into a givenzone or group of zones, or because unforeseen conditions such as heatgenerating equipment or external sunlight exposure were not taken intoaccount.

In such a situation, the air distribution system can use its broadcastfunction to cause a particular zone or group of zones to rebalance alocalized portion of the air distribution system. The localizedbalancing is similar to system balancing on a more restrictive scale.Each controller 68 is provided with an airflow setpoint. When instructedto do so by the building automation system 76, the controller 68 adjustsits balancing damper 350 until measured airflow approximates the airflowsetpoint. The setup tool 320 can also cause rebalancing to occur.

Additionally, indications of personal discomfort as received from thepersonal comfort sensors 110 using the comfort indication input 358 canbe logged. If a pattern emerges that a particular zone or group of zonesis consistently too warm or too cold, a particular controller 68 canautomatically initiate rebalancing of its particular zone to a newairflow setpoint which may be adjusted, for example, by a factor of 5percent from the previous airflow setpoint. The controller 68 may itselfalso request that the building automation system 76 evaluate rebalancingthe particular group of zones that the controller 68 is a member of. Ifthe controller 68 is provided with the identification codes of the othercontroller 68 in its particular localized portion of the airdistribution system, the controller 68 can issue a broadcast messagedirectly to those controllers 68 to initiate a localized rebalancing ofthe air distribution system.

The communications media described, including those of the first andthird communications media TX1, TX2 and TX3, may conform to thecommunications protocol standards being developed by the ASHRAESTANDARDS PROJECT Committee as defined in "BACNet-A Data CommunicationsProtocol for Building Automation and Control Networks, Working Draft No.4", SPC-135P-.015, ASHRAE 1990. This publication is hereby incorporatedby reference. The BACNet-A Data Communications Protocol addressesgeneral system broadcasts, specific transmissions and treatment ofexisting proprietary protocols.

It should be recognized that modifications and alterations of thepresent invention as described and suggested herein are possible. Suchmodifications include a number of alternative wireless transmissionsmedia for the second communications media, as well as variations in thethird communications medium. Additionally, the volume and type ofinformation transmitted can be varied as well as the uses to which thecontroller puts that information. Also, the zone or personal comfortsensors could include the capability to selectively transmit on eitheror both of the second and third communications media. Furthermore, thepresent invention can be applied to areas of air distribution such assystem air balancing to improve those areas. Additionally, the type ofchiller elements used as well as the controller application may vary.Also, the controller can combine or prioritize information from a numberof sensors as described or suggested herein. Finally, the controllersreferred to herein are not intended to be limited to control of airflow,and the invention is intended to encompass all applications requiringthe transfer of data between a sensor and a controller. All suchmodifications and alterations are intended and contemplated to withinthe spirit and scope of the present invention.

What is desired to be secured by Letters Patent of the United States isclaimed as follows:
 1. A hierarchical control system comprising:a firstcentral receiver; a first communications medium operably connecting thefirst central receiver to at least one controller; a controller operablyconnected to the first central receiver by the first communicationsmedium; a first sensor sensing conditions; a second communicationmedium; a first transmitter transmitting the sensed conditions from thefirst sensor to the first central receiver via the second communicationsmedium, the first central receiver including a first receiver receivingtransmissions on the second communications medium and a secondtransmitter retransmitting the transmissions on the first communicationsmedium; the system including a second sensor sensing conditions, thesecond sensor including a third transmitter transmitting the sensedconditions to the first central receiver via the second communicationsmedium; and the controller including means for determining a failure ofthe first sensor, and means for substituting the sensed conditions fromthe second sensor for the sensed conditions of the first sensor.
 2. Thesystem of claim 1 wherein the second communication medium is a wirelessmedium.
 3. The system of claim 2 wherein the second communication mediumis spread spectrum radio frequency communications.
 4. The system ofclaim 2 wherein the second communication medium is infraredcommunications or radio frequency communications.
 5. A hierarchicalcontrol system comprising:a first central receiver; a firstcommunications medium operably connecting the first central receiver toat least one controller; a controller operably connected to the firstcentral receiver by the first communications medium; a first sensorsensing conditions; a second communications medium; a first transmittertransmitting the sensed conditions from the first sensor to the firstcentral receiver via the second communications medium, the first centralreceiver including a receiver receiving transmissions on the secondcommunications medium and a second transmitter retransmitting thetransmissions on the first communications medium; a third communicationsmedium; and a third sensor sensing conditions, the third sensorincluding a third transmitter transmitting the sensed conditions on thethird communications medium; wherein the first sensor includes areceiver receiving sensed conditions transmitted on the thirdcommunications medium, and means for retransmitting transmissions fromthe third communications medium on the second transmissions medium. 6.The system of claim 5 wherein the third sensor includes an inputconnector and means for identifying and processing data received throughthe input connector.
 7. A hierarchical control system comprising:a firstcentral receiver; a first communications medium operably connecting thefirst central receiver to at least one controller; a controller operablyconnected to the first central receiver by the first communicationsmedium; a first sensor sensing conditions; a second communicationsmedium; and a first transmitter transmitting the sensed conditions fromthe first sensor to the first central receiver via the secondcommunications medium, the first central receiver including a firstreceiver receiving transmissions on the second communications medium andretransmitting the transmissions on the first communications mediumwherein the controller includes means for operating independently of aparticular sensor.
 8. The system of claim 7 wherein the independentoperating means includes means for substituting a predetermined defaultsensor whenever a predetermined time period has expired withoutreceiving a transmission from the first condition sensing means.
 9. Thesystem of claim 7 wherein the first sensor is portable and includes aself-contained source or means for receiving power from an externalpower source.
 10. The system of claim 7 wherein the first sensorincludes at least two sensors, and the independent operating meansincludes means for combining the data from the sensors.
 11. The systemof claim 10 wherein the combining means includes means for averaging thedata from the sensors.
 12. The system of claim 10 wherein the combiningmeans includes means for prioritizing the data from the sensors.
 13. Thesystem of claim 10 wherein the combining means includes means foroperating in a mode of operation determined by the data from themajority of the sensors.
 14. The system of claim 7 further includingmeans for providing supplemental conditioned air to localized areaswithin an environment in response to an occupant's signal.
 15. Thesystem of claim 7 including at least a second central receiver operablyconnected to the at least one controller, the second central receiverincluding a second receiver receiving transmissions on the secondcommunications medium.
 16. The system of claim 15 wherein the secondcentral receiver functions as a backup to the first central receiver.17. The system of claim 15 wherein the second central receiver operatesindependently of the first central receiver.
 18. The system of claim 17wherein the first and second central receivers are associated withseparate floors of a building.
 19. The system of claim 18 furtherincluding third and fourth central receivers respectively acting asbackups for the first and second central receivers.
 20. The system ofclaim 1 wherein the first sensor includes an input connector and meansfor identifying and processing data received from the input connector.21. A system for transferring information from a sensor to a controllercomprising:a first communications medium; a second wirelesscommunications medium; a controller operably connected to the firstcommunications medium; a receiver operably connected to the firstcommunications medium, receiving communications on the secondcommunications medium and retransmitting communications from the secondcommunications medium on the first communications medium; a first sensorsensing conditions, and transmitting the sensed conditions on the secondcommunications medium to the controller by means of the first and secondcommunications medium; a third communications medium; and a secondsensor sensing a condition and transmitting the sensed condition on thethird communications medium; wherein the first sensor includes areceiver receiving communications on the third communications medium,and retransmitting communications from the third communications media onthe second communications medium.
 22. The system of claim 21 wherein thethird communications medium is wireless.
 23. The system of claim 21wherein the first communications medium is a cable or a twisted wirepair or a power line carrier and the second communications medium iswireless.
 24. The system of claim 21 wherein the third communicationsmedium is infrared communications, ultrasonic communications, or radiofrequency communications.
 25. The system of claim 21 wherein the secondcommunications medium is spread spectrum radio frequency communications.26. The system of claim 25 wherein the third communications medium isspread spectrum radio frequency, and wherein the third communicationsmedium operates either using a different frequency than the secondcommunications medium, or using a different spreading algorithm than thesecond communications medium.
 27. The system of claim 21 wherein thethird communications medium is a fiber optic link, a cable link or atwisted wire pair link.
 28. The system of claim 21 including an inputconnector operatively associated with the first sensor.
 29. The systemof claim 28 wherein the first sensor is portable and includes aninternal power supply.
 30. A building HVAC and automation systemcomprising:means for conditioning air; means, operably connected to theconditioning means, for distributing the conditioned air; a firstcommunications medium, an automation system, operably connected to theconditioning means and the distributing means, controlling thedistribution of conditioned air, the automation system including aplurality of controllers operably connected to the first communicationsmedium; a second wireless communications medium; at least one centralreceiver operably connected to the first communications medium andincluding a first receiver receiving transmissions on the secondcommunications medium and retransmitting the communications from thesecond communications medium onto the first communications medium; aplurality of zone sensors, each zone sensor including a sensor sensingenvironmental conditions and a first transmitter transmitting dataindicative of the sensed environmental conditions on the secondcommunications medium; wherein at least some of the plurality ofcontrollers control the distribution of air in accordance with thetransmitted data; wherein at least a first controller of said pluralityof controllers distributes air in accordance with the transmitted datareceived and combined from more than one of the plurality of zonesensors.
 31. The system of claim 30 wherein at least some of theplurality of zone sensors include an input connector adapted to receiveany of one of a plurality of sensors.
 32. The system of claim 30 whereinthe first controller averages the transmitted data from more than one ofthe plurality of zone sensors.
 33. The system of claim 30 wherein thefirst controller distributes air in accordance with the transmitted dataof a majority of the more than one of the plurality of zone sensors. 34.The system of claim 30 wherein each of the plurality of zone sensorsincludes means for entering a dormant state to conserve power, and meansfor awaking from the dormant state.
 35. The system of claim 30 whereinthe second communications medium is a radio frequency, an ultrasonic, aninfrared, or a spread spectrum radio frequency medium.
 36. The system ofclaim 35 wherein the first communications medium is a cable link, atwisted pair link, or a fiber optic link.
 37. A method of controlling anenvironment comprising the steps of:determining, with at least a firstsensor, the environmental conditions in each of a plurality of zones;transmitting signals indicative of the environmental conditions fromeach of said plurality of zones to a central receiver by means of asecond communications medium; receiving the environmental conditions atthe central receiver from the second communications medium;retransmitting the environmental conditions from the central receiveronto a first communications medium; receiving in each of a plurality ofcontrollers the retransmitted environmental conditions on the firstcommunications medium; and controlling the environment of a particularzone in accordance with a predetermined portion of the environmentalconditions from several sensors.
 38. The method of claim 37 includingthe step of controlling the environment of the particular zone byaveraging the environmental conditions from several sensors.
 39. Themethod of claim 37 including the step of controlling the environment ofthe particular zone by prioritizing the environmental conditions fromseveral sensors.
 40. The method of claim 37 including the step ofdetermining mode of operation of an air distribution based upon theenvironmental conditions of a majority of the plurality of zones. 41.The method of claim 37 including the step of providing an inputconnector in the first sensor where the input connector includes meansfor allowing an external sensor to be attached to the first sensor, thefirst sensor including means for recognizing the attachment of anexternal sensor to the input connector, identifying the type of externaldevice attached to the input connector, and thereafter operating theexternal device in a conventional manner.
 42. The method of claim 41 ofthe first sensor including the steps of attaching a second sensor to theinput connector of the first sensor, measuring data using the secondsensor, and forwarding that data to the respective controller by meansof the second communications medium, the central receiver and the firstcommunication medium.
 43. A hierarchical control system comprising:afirst central receiver; a first communications medium operablyconnecting the first central receiver to at least one controller; acontroller operably connected to the first central receiver by the firstcommunications medium; a first sensor sensing conditions; a secondcommunication medium; a first transmitter transmitting the sensedconditions from the first sensor to the first central receiver via thesecond communications medium; the first central receiver including afirst receiver receiving transmissions on the second communicationsmedium and retransmitting the transmissions on the first communicationsmedium; a third communications medium; a second sensor sensingconditions, the second sensor including a second transmittertransmitting the sensed conditions on the third communications medium;the first sensor including a second receiver receiving sensed conditionstransmitted on the third communications medium, and retransmittingtransmissions from the third communications medium on the secondtransmissions medium; an input connector and means for identifying andprocessing data received from the input connector; and a setup toolproviding programming instructions to the controller, and including athird transmitter transmitting the programming instructions on thesecond or third communications medium.